The invention provides a method for correcting well shaft pressure in real time, and belongs to the technical field of petroleum drilling engineering. The method comprises the following steps: computing, according to basic parameters of bored well shaft pressure and pressure-controlled drilling boundary conditions, to obtain an annular pressure loss value before correcting of a to-be-measured well, and computing to obtain a hydrostatic column pressure value of the to-be-measured well; acquiring a practically-measured well bottom pressure value of the to-be-measured well by virtue of a pressure monitoring system while drilling PWD, and correcting, based on the pressure conservation principle, any one of well shaft pressure, wherein the well shaft pressure comprises well bottom pressure, annular pressure loss and well-mouth return pressure. According to the method provided by the invention, the well shaft pressure data is acquired based on the pressure conservation principle, and the well shaft pressure is corrected in real time by virtue of well shaft pressure data acquired by the PWD, so that the method has the characteristic that the correction for the well shaft pressure is simple, convenient, quick, and relatively high in precision; moreover, complex mesh generation and discrete solution on a control equation set are not required, so that requirements on performance of a computer are relatively low, and therefore, the method is more suitable for a site working condition for drilling construction.