Process parameter optimization is important for improving the lapping effect of optical elements. Based on a temperature-controlled lapping disc, we present a method using fuzzy theory and orthogonal experiment to optimize lapping process parameters. Unlike the theory of optimization target set with a single evaluation criterion, a comprehensive optimization target with multiple evaluation criteria based on a fuzzy algorithm is proposed in this method. The lapping disc temperature, lapping disc rotation speed, and lapping pressure were selected as the optimization process parameters, and the material removal rate (MRR), surface change uniformity (SCU), and fuzzy synthetic index of lapping (FSILAP) were used as the optimization targets to conduct comparative experiments and analysis. The experimental results showed that when using the optimal process parameter combination obtained by the comprehensive index FSILAP as the optimization target, balanced results for MRR and SCU could be obtained. Notably, the result obtained when using a single evaluation criterion as the optimization target was suboptimal. The proposed method is effective and practical for the optimization of lapping process parameters.