The invention relates to a power generation system utilizing waste heat of a torch. The power generation system comprises a guide cylinder erected above the torch and a sealing shell. A steam power generation mechanism is arranged in the sealing shell. The upper end and the lower end of the guide cylinder are open. An evaporation pipeline is arranged in the guide cylinder and comprises at least one evaporation heat exchange pipe. A condensation pipeline is arranged outside the guide cylinder and comprises at least one condensation heat exchange pipe. A working medium outlet of the evaporation pipeline communicates with an inner cavity of the sealing shell. A working medium inlet end of the condensation pipeline is connected with the bottom of the sealing shell and communicates with the inner cavity of the sealing shell. A working medium outlet of the condensation pipeline communicates with a working medium inlet of the evaporation pipeline. The power generation system provided by the embodiment is simple and compact in structure and high in safety, does not affect operation of the torch, can effectively utilize the waste heat of the torch, and improves the economic benefits.