Abstract: The analysis on problems existed in the negative pressure crude stabilization units of two multi-purpose stations in Zhongyuan oilfield has been made. With ASPEN-PLUS software, a simulation calculation on equilibrium vaporation and equilibrium cooling of oil stabilizer has been carried out in order to determine the optimum technology parameters. On this base, the technical modification on negative pressure crude stabilizer has been conducted. In this paper, the economic profits obtained from the technological modification is given.