The invention discloses a preparation method of Ti3SiC2/Ag composite conductive powder. The preparation method comprises the steps of (1) performing alcohol washing, coarsening, sensitization, activation, water washing and drying on Ti3SiC2 powder in sequence, so that pretreated Ti3SiC2 powder is obtained; (2) respectively preparing a silver-ammonia solution and a reduction solution; (3) performing silver and ammonia plating on the pretreated Ti3SiC2 powder obtained in the step (1) by utilizing the silver-ammonia solution and the reduction solution which are obtained in the step (2); and (4) filtering residual substances after the plating in the step (3) is completed, and drying the residual part after liquid is filtered, so that the Ti3SiC2/Ag composite conductive powder is obtained. By adopting the preparation method, the Ti3SiC2/Ag composite conductive powder with low density, good stability and high electric conductivity can be prepared.