The invention relates to a manufacturing method for a honeycomb sealing device of a combustion gas turbine. The method resolves the problem that an existing manufacturing method of the honeycomb sealing device is poor in manufacturing effect and low in manufacturing efficiency. The method includes the following steps: step1 cleaning a surface; step 2 stacking a honeycomb; step3 repeating the step 1 and the step 2, and enabling all honeycomb eyes on the honeycomb sealing device to be filled with polymethyl methacrylate homopolymerize powder and be added with methyl methacrylate liquid; step 4 after the polymethyl methacrylate homopolymerize powder and methyl methacrylate are subjected to reaction, enabling the polymethyl methacrylate homopolymerize powder and methyl methacrylate to be subjected to reaction to form polymer to be fully filled into existing gaps inside the honeycomb holes; step 5 adopting a grinding method to conduct pitching-in-way processing for the honeycomb sealing device after completing the step 4, selecting a brown aluminium oxide grinding wheel to be a grinding wheel; step 6 conducting remaining filling polymer gasification processing. The manufacturing method is used for manufacturing the honeycomb sealing device of the combustion gas turbine.