The purpose of this paper is to provide reference for safety warning and accident recovery of tank truck rollover. The calculation method of critical lateral acceleration of tank truck considering liquid sloshing is studied by combining analytical method and multi-body dynamics simulation method. In this paper, three methods are presented to solve the critical lateral acceleration of tank truck rollover considering liquid sloshing, which are analytical method, step steer simulation method and tilt table simulation method respectively. The liquid sloshing is simplified to two-dimensional liquid sloshing by assuming that the lateral acceleration of the tank truck is constant. The change of liquid center of gravity is used to be equivalent to the effect of liquid sloshing on tank truck rollover. The influence data of liquid sloshing, tire, suspension system and tank truck center of gravity on the rollover of tank truck were obtained. The research results can be applied to the safety warning and accident recovery of tank truck.