The invention relates to the technical field of three-dimensional rendering loading optimization, in particular to a digital three-dimensional scene rendering performance optimization method, which comprises the following steps of S1, defining a model of which the parameter value is greater than or equal to a parameter preset value as a heavy model, and marking the heavy model; s2, judging whether the heavy model in the digital three-dimensional scene is completely shielded or not, removing the completely shielded heavy model, and generating a proxy geometry at an original position; and S3, if the distance between the model and the camera is greater than or equal to the preset distance value, reducing the resolution, and if the distance between the model and the camera is less than the preset distance value, improving the resolution. According to the method, the key equipment model in the three-dimensional scene is selectively optimized by combining the proxy geometry through the shielding query and the LOD technology, so that the overall performance and smoothness are improved on the premise of ensuring the rendering quality.