Garrison in WOD brings much fun to WOW. For players, it is a home they own that they can do everything. The most popular in Garrison are Storehouse, Transmogrification, and Auction House. How to build the Auction House in Garrison is a major headache for many players, would you like to create your auction in Garrison?
First of all, you need a Trading Post and upgrade to level 2. Then you'll find there is a broken Ancient Trading Mechanism in your Trading Post, and get a quest to obtain five modules to build auction house.
Arcane Crystal Module 
Auction Control Module 
Super Cooling Module 

Cyclical Power Module

 Every module is made up of several small parts which can drop from Ashran, raid, and Dungeons. Obtaining the parts will be a long grind. The fast way is to buy modules from AH with a large amount of wow gold.

If you don not know how to create the module, with the parts in your inventory just right click one after you have obtained at least one of each module's parts, the system will prompt which modules you still need. Just follow the prompt to get or buy these tiny parts. This method will help you fast complete the quest.
After obtained the five modules, you can back to Ancient Trading Mechanism in Garrison to submit quest. Then you built your own Garrison Auction House. The Auction will bring you great convenience.