Process system for energy saving transformation of urea device

The invention discloses a process system for energy saving transformation of a urea device. The process system comprises a gas stripping tower, a medium pressure decomposing tower, a medium decomposing device, a rectification tower and a urea liquid extraction tower, wherein the medium pressure decomposing tower comprises a filler tower and a first separator; the gas stripping tower is communicated with a feeding opening of the filler tower through a pipeline; a first regulation valve used for regulating pressure intensity is arranged on the pipeline for communicating the filler tower with thegas stripping tower; the medium pressure decomposing device is communicated with a liquid outlet of the filler tower through a pipeline; the medium pressure decomposing device is used for heating materials inside; a feeding opening of the first separator is communicated with the medium pressure decomposing device through a pipeline; an exhaust opening of the medium pressure decomposing device iscommunicated with a gas in