The invention provides a laser and grating coupler packaging structure and method. The packaging structure comprises a laser unit, a collimating lens, an isolator and a reflection prism, wherein the laser unit, the collimating lens, the isolator and the reflection prism are mounted on a silicon-based photoelectric chip. The silicon-based photoelectric chip comprises a first electrode, first and second marks, a grating coupler and a waveguide layer which are all arranged at the surface; the laser unit comprises a transitional substrate and a laser; the collimating lens comprises a first lens and a second lens, the first lens is vertical to the surface, the second lens is arranged at the surface at the position of the second mark, and thus, the grating coupler is placed in the central area of the main axis of the optical path of the second lens; and the isolator is mounted at the surface between the first lens and the second lens, so that diverging light output by the laser is collimated by the first lens, then reflected to the reflection prism through the isolator, deflected by the reflection prism for certain angle, and gathered by the second lens, and the gathering point is placed at the surface of the grating coupler. Thus, technical problems in accurate in-place packaging are solved, convenience is provided for preparation, and the yield rate is improved.