In recent years, the field of 3D printing technology has experienced rapid advancements, notably expanding its application within the medical sector. This study focuses on the custom design of 3D-printed spinal implants, specifically examining porous interbody fusion products. It integrates considerations of mechanical strength and bone ingrowth to establish a finite element model of porous interbody fusion, subsequently conducting topology optimization to design three distinct types of spinal interbody fusion implants. Analytical investigations were carried out on the stress and displacement responses of these three implant types under compressive loading. Furthermore, a detailed stress analysis was conducted on implants varying in porosity, length, and screw angle of the bone graft to assess the performance characteristics of the porous interbody fusion devices. Results indicated that the Type C implant exhibited superior performance, demonstrating a stress reduction to 89.21 MPa and a displacement change of 0.006 mm, optimally at a 60% porosity level. Adjustments in the lengths and screw clamp angles of the splint ensured that the maximal stress experienced by each vertebra remained below the yield limits of both cortical and cancellous bone, thus preventing vertebral damage. This paper presents a comparative analysis of three types of porous interbody fusion devices, providing substantial data support and a theoretical framework that can inform the future development of fusion products.