Disclosed is a device for preparing multi-component metal hydroxide including a raw material feeder configured to feed raw materials including a metal raw material, a pH adjuster and a complexing agent, a reactor configured to react the raw materials fed from the raw material feeder to prepare a reaction solution and grow particles of multi-component metal hydroxide contained in the reaction solution, a storage tank configured to store the reaction solution transferred from the reactor, a first duct configured to transfer the raw materials from the raw material feeder to the reactor, a second duct configured to transfer the reaction solution from the reactor to the storage tank, a third duct configured to transfer the reaction solution from the storage tank to the reactor, and an operation controller configured to control operations of the reactor and the storage tank to circulate the reaction solution between the reactor and the storage tank until the particles of multi-component metal hydroxide grow to a target particle size.