The invention discloses an ECC encryption module for safe transmission of a power system. The ECC encryption module is provided with a minimum clock period (LCC) modular inverse hardware structure which comprises a plurality of modular 2n power devices, a modular multiplier, a first multiplexer, a second multiplexer, a third multiplexer, a first input end, a second input end, a first output end, asecond output end, and a control module, wherein each modular 2n power device comprises a modular square unit; the output end of the modular multiplier is respectively connected with the input ends of the plurality of modular 2n power devices; the first multiplexer is arranged at the input end of the modular square unit; the second multiplexer is arranged at the output ends of the plurality of modular 2n power devices; the third multiplexer is arranged at the input end of the modular multiplier; the first input end and the second input end are respectively used for inputting operands; the first output end and the second output end are respectively used for outputting a modular inverse result and a modular division result; and the control module is used for controlling path selection of the plurality of multiplexers. The ECC encryption module provided by the invention can effectively shorten the critical path, thereby reducing the calculation delay.