Abstract: Aimed at the characteristics of large deployable truss antenna with many trusses and joints, surface error and repetitive deployable precision of antenna with tolerances of trusses and joints clearances were studied. Considered the randomicity of tolerances of trusses and joints clearances, a stochastic finite element model of deployable truss antenna used Monte-Carlo method was developed to simulate the root mean square of surface error. It is shown that the value of root mean square of surface error caused by joints clearances is much larger than that from tolerances of trusses, and the repetitive deployable precision error of antenna can not be neglected.