Based on similar single-phase flux-switching permanent magnet linear motor (FSPMLM), a comparable modular longitudinal FSPMLM (LFSPMLM) and transverse FSPMLM (TFSPMLM) are presented and investigated in this article. The modular LFSPMLM and TFSPMLM have no magnetic coupling among modules. Single-phase piecewise-linear inductance models of LFSPMLM and TFSPMLM are proposed, and corresponding comparative studies are conducted. Comparative calculation results show that an optimized design scheme is established, and a set of structural parameter is proposed. The results of finite element analysis (FEA) show that the LFSPMLM has higher efficiency than TFSPMLM. However, the TFSPMLM has a small detent force, and controlling its thrust force performance is feasible. Prototype experiments of no-load detent force and average thrust force are performed, and the experimental results agree with the FEA results. This finding further verifies the conclusions of comparative investigation on characteristics between the proposed LFSPMLM and TFSPMLM.