The coordinated optimal operation of transmission and distribution networks is a promising solution for optimally allocating the generating resources in multi-level power grids and accommodating large-scale distributed renewable energy. However, for the coordinative operation models of transmission and distribution networks, the traditional iteration-based solving approaches have great limitations in computational performance and institutional mechanisms. Thus, a coordinative optimal operation method of transmission and distribution networks based on multi-parametric programming is proposed, in which the operational information of distribution networks is completely characterized. The proposed method has great numerical calculation stability and it is compatible with the current dispatching management mechanism. Case studies are presented to verify the effectiveness of the proposed method and discuss the influence of various factors. The results indicate that the synergistic effect of transmission and distribution networks is realized, and the optimalized dispatch results is satisfied. Meanwhile, the increase in wind power penetration level and installed capacity in distribution networks can both help to reduce total operation cost.