The sensitive chip of quartz MEMS gyroscope usually adopts the double ended tuning fork structure. The vibration coupling error which comes from the drive and detection tuning forks is the main error source. The structure decoupling design and simulation of the sensitive chip with doubleend tuning fork have been carried out in this paper. The impact of chip mounting area on the vibration characteristics of the detection tuning fork has been analyzed. The bias error signal of gyroscope has been reduced and the stability of the sensitive chip has been improved by using the proposed decoupling design.