Aiming at the solution of low communication rate, stability and anti-interference problem of Li-lion formation and test equipment, two controllers of TMS320F2812 DSP as lower controller and ARM as upper controller, are introduced as Controller Area Network (CAN) communicaton model in formation and test system to realize high speed and stable communication between bottom and top. This paper presents a scheme of using CAN technology to realize communication. The principle and communication protocol of formation and test system and hradware design are introduced in this paper.