Abstract: In application of Beidou single frequency receiver in real time mining deformation monitoring, in order to improve precision of cycle slip detection in measurement preconditioning of Beidou single frequency carrier phase, real time cycle slip detection of Beidou single frequency carrier phase based on Kalman filtering was proposed, and recognition method of gross errors and cycle slips was discussed. The experiment was carried out with the Beidou single frequency carrier phase data collected in a certain mining area, the results show that the method can efficiently, sensitively and real-timely detect the location of cycle slip.