The work aims to study the new structure of the internal meshing globoidal cam mechanism, deduct its profile equation and analyse its working performance, to provide theoretical basis for its structure design. Based on the theory of conjugate surface and the principle of differential geometry, the equations of convex profile surface of internal meshing and calculation formula of pressure angle were derived combined with the theory of geometric coordinate transformation. The pressure angle calculation results were obtained and analysed with Matlab. Finally, 3D modelling and Adams variable input motion simulation were carried out. The profile equation of internal meshing globoidal cam and the influencing factors of pressure angle were obtained. The motion law of follower had a significant effect on the maximum pressure angle. The smaller the diameter ratio was, the smaller the pressure angle was. The theoretical research on the new form of globoidal cam mechanism expands the application field of globoidal cam mechanism and provides theoretical basis for its structural design.