In order to meet the requirements of large field of view, large exit pupil, high imaging quality and light and small structure of virtual reality head-mounted display, a reverse optical path design method was adopted to study pancake structure of a folding optical path. Two lenses were designed for theoretical analysis and software simulation, and the tolerance analysis of the designed optical system was carried out. The results show that the full field Angle is 96°, the exit pupil diameter is 10 mm, the exit pupil distance is 14.94 mm, the modulation transfer function (MTF) is greater than 0.2 at Nyquist frequency (20.83 lp/mm), the maximum distortion is -26.5%, and the maximum vertical color difference is 13.84 μm, respectively. This structure has higher MTF value, smaller vertical color difference and root mean square radius of dispersion class, and reasonable aberration balance. This study provides a reference for the folding optical path structure of the head-mounted display.