Bedsore is a common disease for long-term bedridden patients,electronic treatment instruments can effectively prevent the occurrence of bedsore.In this paper,stress sensor and micro-controller are used to sample pressure signal of each part of the body and send the signal to PC by RS232.LabVIEW virtual instrument is designed to analyze the measure pressure data,and estimate the state of every parts of the human body that have been continuously pressed.Then the LabVIEW instrument will send control signals to the corresponding pumps of the mattress.This instrument can prevent human skins being pressed too long in part areas.