Forced cooling type built-in battery pack cooling device for electric vehicle

A forced cooling type built-in battery pack cooling device for an electric vehicle comprises multichannel micro-groove composite phase-change cooling modules which are connected to each of two lateral heat surfaces of each battery in a battery pack respectively. Each multichannel micro-groove composite phase-change cooling module is an I-shaped cooling module formed by connection of one cavity and two wing fins, and the two lateral heat surfaces of each battery are respectively connected with the corresponding cavity. The multichannel micro-groove composite phase-change cooling modules in pairwise interleaved contact to form a row, and a channel clearance convenient for insulating cooling liquid to flow is reserved between each two adjacent rows of the multichannel micro-groove composite phase-change cooling modules. The batteries and the multichannel micro-groove composite phase-change cooling modules are mounted in a battery pack case, and each of upper and lower surfaces of the battery pack case is provided with a liquid inlet and a liquid outlet for the insulating cooling liquid.