The dimension of 65 mm×200 mm ceriumdoped lutetium oxyorthosilicate crystals were grown by the Czochralski method. Based on the study of high lightoutput uniformity mechanism, the orthogonal experiment was adopted to grow Ce:LSO crystals with different cerium concentrations, SiO2 compensated concentrations and crystallization ratio. Considering the result of relative light output and uniformity from head and bottom, the appropriate parameters of raw material ratio and crystallinity were demonstrated, that is, the ceriumdoped concentration is 0.16%, the SiO2 compensated compensated is 0.20% and the crystallization ratio is 60%. The test results show that the lightoutput uniformity can be increase to more than 96%.