Abstract: Multi-sensor data fusion is a new technique developed in recent years, which is now widely applied to military and civilian areas. This paper discusses basic principles and processes of multi-sensor fusion and puts forward a detecting scheme of dip and azimuth angle of a drilling hole according to the characteristics and demand of the automatic vertical drilling detecting system. Meanwhile, it presents two data fusion methods: one being based on the arithmetic average and expandable estimate for the vertical drilling system and the other, based on the arithmetic average and estimate in batch for the vertical drilling system. These methods can improve the anti-jamming ability of automatic vertical drilling detecting system in order to assure the parameter reliability and veracity of collecting datum.