Abstract: In back-pressure dropping technique in oilfield, water bathed heater of wellhead works with high consumption of water/power and low rate of heat exchange. Therefore, a technical modification on the traditional water bathed heater of wellhead is made by applying high boiling point superconductive liquid and new type heat exchange heater. Aiming at the high loss in gas venting in multifunction tank stored products, several techniques such as residential gas recovery of multifunctional tank, cased gas inputting system, flank well compressor recovery areadopted to solve those problems. Proved by real engineering project, this technique is beneficial to the residual gas recovery with backpressure dropping technique for the wellhead of oilfield with low cost and high economic and social benefits.