[ $YBa_2Cu_3O_{7-{delta}}$ ] superconductor films have been prepared on silver substrates by electrophoretic deposition. As silver does not react with $YBa_2Cu_3O_{7-{delta}}$ compound and has little influence on its superconductivity, it is usually doped in $YBa_2Cu_3O_7$ to improve the strength of the material and eliminate micro cracks. It has been proved that Ag additive can lower the melting temperature of $YBa_2Cu_3O_{7-{delta}}$ and act as linking bridge among $YBa_2Cu_3O_{7-{delta}}$ particles, thus in this paper Ag doped $YBa_2Cu_3O_{7-{delta}}$ thick films are prepared by electrophoretic co deposition. As there are only some referenced experience formula and models for co electrophoretic deposition and does not exist unified explanation, the behavior of Ag particles during co electrophoretic deposition is also studied.