A double stator permanent magnet cursor linear motor and a design method for increasing magnetic field modulation effect. The motor comprises a motor primary (1), a first secondary (6) and a second secondary (7). The first secondary (6) and the second secondary (7) are arranged at the two sides of the primary (1) respectively and separated by an air gap (9) therebetween. The first secondary (6) and the second secondary (7) of the motor comprise modulated teeth (8). The primary (1) of the motor is of a bilateral symmetrical structure. A permanent magnet (2) is embedded in a yoke section of an iron core unit (2) of the primary. The above motor solves the problem of the magnetic flux leakage at the end of the permanent magnet which is inherent in the conventional permanent magnet cursor motor, and improves the utilization rate of the permanent magnet, and therefore improves the thrust density of the motor. In addition, each of the two secondaries of the motor is made of laminated silicon steel sheets; for linear long-travel applications, such logistics transportation lines and rail transportation lines, permanent magnet materials can be saved, thus greatly reducing costs. The above design method can, through adjusting the structure parameters of the permanent magnet, conduct repeated calculation by means of a finite element calculation method to obtain the corresponding structure parameters of the permanent magnet of the permanent magnet motor in the case of the maximum amplitude of the back electromotive force of the permanent magnet motor.