a process for preparing trifluorochloroethylene including : in a multi - tubular reactor , hydrogenation reacting 1 , 1 , 2 - trifluoro - 1 , 2 , 2 - trichloroethane directly with a catalyst potassium zinc trihydride to obtain trifluorochloroethylene , wherein the catalytic reaction is performed at a temperature of 250 - 350 ° c . and a pressure of 0 . 7 - 1 . 0 mpa for 10 - 20 seconds . the conventional process in which zinc powder is used for dechlorination or hydrogen is used for dechlorination through hydrogenation with the action of a noble metal catalyst is avoided in the process disclosed herein . the present process substantially reduces the production cost of trifluorochloroethylene , and substantially increases the product yield , which can be up to 99 % or more .