Considering the flexibility of the aircraft in low-altitude airspace, we put forward a flight conflict detection algorithm adaptable to the low-attitude airspace flight based on conflict probability.In the algorithm, the spatial precision and time parameters were taken into account, the indefinite integral of the extended conflict area in the direction of the relative motion of Paielli algorithm, is changed into a definite integral corresponding to the conflict time, which has determined upper and lower limits of integration.The conflict probability is transformed into the integral of the cross volume between the collision area and the joint track error corresponding to a certain moment.The quantization solution of the conflict probability model is realized by Cholesky factorization and matrix rotation, which is more accurate for the prediction of the conflict probability.