In consideration of the strength and safety

both distribution's density and function's density were integrated to induce the conservative fuzzy reliability design formulas about engine connecting rod

namely

the stress

strength

geometry dimension of component etc

were normally distributed

and subordinate function was obtained from fuzzy reliability design formula in the case of parabola of exponential k;the numeric result about the conservative fuzzy reliability design of engine connecting rod was achieved by VBprogram in the computer.This program can be used in design of connecting rod to improve the level of design.