The fast temperature ramping Hg‐vapor annealing (FTRA) process has been used for growth of superconducting Hg‐based cuprate thin films on (100) LaAlO3 substrates. The film/substrate interface chemical reactions and the formation of a CaHgO2 impurity phase have been effectively reduced with adoption of the FTRA process. A zero‐resistance superconducting transition temperature of 128 K and critical current densities of up to 1.4×106 A/cm2 at 77 K and 2.5×105 A/cm2 at 110 K and zero field have been obtained.