The invention provides a building inclination angle prediction method and system. The method comprises the following steps: reading and inputting an inclination angle measurement value into a data matrix; according to a matrix decomposition method and a gradient descent method, fitting the inclination angle measurement value in the data matrix to obtain inclination angle predication values corresponding to all points in the data matrix, and outputting the inclination angle predication values when the preset conditions are met; saving data of the wind direction and the wind speed at the points, corresponding to the inclination angle predication values which exceed the inclination angle threshold, in the data matrix to form an inclination-prone wind direction and wind speed data set; comparing the predication values of the wind direction and the wind speed in an environment where a building is positioned with the data of the wind direction and the wind speed at such points in the easy-inclination wind direction and wind speed data set; when the predication value falls into a preset range, sending an early warning signal. Through the adoption of the method and the system, the inclination angle of the building in the preset wind direction and wind speed conditions can be predicted, so that the wind direction and wind speed corresponding to the situation that the building is prone to inclination can be obtained, the warning function is achieved, and the building is prevented from collapsing.