I have my own shopify store and sell wholesale. How do I encourage customers to buy from me rather than my stockists?

First, if your business plan depends on sales via your stockists, you want to make sure the methods you undertake do not undermine this revenue stream. Most merchants do not relish competing with their suppliers, though in this day and age is more expected. (When I was acting as a reseller, I started purchasing from Amazon.com because the pricing beat my wholesalers, who were also competing with me.) So, when determining your direct strategy, keep this in mind.

With this in mind, the next step is to build a direct sales strategy. This really only has two pieces. The first is determine how you want to differentiate yourself. Generally, when the wholesaler sells direct, the differentiator is price, i.e. "buying direct saves." Of course, you can differentiate on many fronts - customer service, speed, shipping costs, etc. (Just be sure that your pricing / terms don't alienate your stockists.)

The second piece is simply marketing the differentiation. For example, if the focus is on better prices, wholesalers will brand their stores as "Outlets", "Direct Centers", "Buy Direct", etc., which are associated with such savings. From there, it is a matter of creating and advertising mix that combines audience (keywords / demographics) with messages (ad copy / landing pages.)

Hope this gets you started. Let me know if I can be of any further assistance.

I haven't seen your store, so my response is assuming your prices are better, your store doesn't use or rely soly on PayPal and you drop ship as all other things being equal.
The best way for you to get consumers to buy from you is to build relationships with them. Engage consumers with surveys, on social media, be on the look out for users problems and reach to them, create surveys, track what parts of your website are users browsing more and or at what point are they leaving...

Offer dedicated discounts to consumers via Facebook groups. Etc. be creative and build a relationship of trust, friendliness and accessibility.
Also, create offers for referrals.

Put yourself in the buyer's shoes. Why does your customer buy from the retailer rather than from you even though clearly your wholesale prices would be cheaper?

Here are a few reasons:

1. Customers can find the retailer, but they can't find you. Perhaps your retailers spend money, time, and effort on advertising, seo, and web design that you don't.

2. Customers know the retailer, but they don't know you. Probably the retailer has invested in better branding and garnered more consumer trust than you have.

3. Customers have done business with the retailer before, whereas you're an unknown. Most likely, the retailer has accumulated a customer base – even an email list. They enjoy repeat website traffic and can reach out to talk directly to past customers whenever they feel like it. Moreover, they've handled enough transactions to be widely reviewed online and mentioned in social media.

4. Customers find a better experience with the retailer than they'd get with you. Maybe the retailer offers a wider selection of products. Maybe the checkout process, payment, shipping, and customer service are streamlined at the retailer. If you're a 1-man or 1-woman show, then there might be economies of scale at the retailer that you'd find it hard to replicate.

Look at those areas – branding, web design, marketing, customer service, etc. Most likely you'll find gaps between what you offer customers and what the retailer does. Then you can evaluate how to close those gaps and whether doing so is worthwhile.

You can build your own brand while continuing to partner with more established retailers. That's where I would focus, if I were you. Grow awareness.

You might even refer consumers to trusted retailers where they can buy your merchandise. Yes, that means they pay more. Yes, that means you lose a fraction of the money. But your brand gains authority by piggybacking off the reputable brands that feature you. If you regard them as partners, then you might also ask about affiliate commissions for referrals. And that might offset the money you leave on the table by sending your buyers to them.