The invention discloses a front longitudinal beam anti-collision performance design method for a passenger vehicle and aims at solving the problems that when the traditional trial-and-error method is used for designing the front longitudinal beam of a car in the prior art, a computer simulation model needs to be repeatedly modified, the testing needs to be repeatedly carried out, and the like. The front longitudinal beam anti-collision performance design method for the passenger vehicle comprises the following steps that 1, the average crushing counter force expression (shown as the accompanying drawing) of a multi-right-angle cross section thin wall beam is deduced, in the expression, Pm is the average crushing counter force, the unit of the Pm is kN, n is the number of the cross section right angles of the multi-right-angle cross section thin wall beam, M0 is the unit length plastic limit bending moment, the unit of M0 is N.mm, l is the cross section circumference of the multi-right-angle cross section thin wall beam, the unit of the l is mm, h is the wall thickness of the multi-right-angle cross section thin wall beam, and the unit of the h is mm; 2, the cross section of the crushing deformation part of the front longitudinal beam is designed; 3, the average bending moment expression (Mm=(0.3-0.5)Mmax) of a rectangular cross section thin wall beam is deduced, in the expression, Mm is the average bending moment of the rectangular cross section thin wall beam, and the unit of the Mm is N.mm; and 4, the cross section of the bending deformation part of the front longitudinal beam is designed.