The　YBCO　composite　films　doped　with　Ba2YTaO6　(BYTO)　single　nanoparticles　and　BYTO/LaAlO3　(LAO)　double　nanoparticles　were　prepared　by　low-fluorine　MOD　process.　The　result　showed　that　the　optimum　doping　amount　of　BYTO　in　YBCO　film　was　6mol%,　when　the　self-field　J(c)　of　this　film　was　1.25　MA/cm(2),　and　the　maximum　pinning　force　was　3.02　GN/m(3)　at　1.2　T.　In　the　co-doping　experiment,　BYTO　particles　with　positive　lattice　mismatch　with　YBCO　and　LAO　particles　with　negative　lattice　mismatch　with　YBCO　were　introduced,　and　the　interaction　between　two　particles　increased　effective　doping　amount　up　to　10mol%.　With　adjustment　of　the　ratio　of　the　two　kinds　of　nanoparticles,　it　was　found　that　the　6mol%　BYTO+4mol%　LAO-doped　YBCO　composite　films　had　a　J(c)　value　as　high　as　0.27　MA/cm(2)　when　the　magnetic　field　was　2　T.　This　magnetic　field　in　which　the　maximum　pinning　force　was　obtained,　increased　from　0.42　T　for　pure　YBCO　to　1.6　T　for　codoping,　in　which　the　maximum　pinning　force　was　5.6　GN/m(3).　The　co-doping　with　positive　and　negative　lattice　mismatch　nanoparticle　effectively　improves　the　superconductivity　of　YBCO　composite　film　under　applied　magnetic　field.