The utility model relates to a high -speed light electric chip grating passive coupling device, it includes first passive alignment subassembly, the passive alignment subassembly of second and passive coupling subassembly, first passive alignment subassembly includes: a fixed platform, DFB laser instrument silicon are aimed at the platform, are in through the encapsulation of flip chip bonding mode the DFB laser instrument on the platform is aimed at to DFB laser instrument silicon to and first plus lens, the passive alignment subassembly of second includes: to eka silicon platform subassembly, optical interface component and through to eka silicon platform subassembly and the fixed fiber array of optical interface component, to being equipped with the second plus lens on the eka silicon platform subassembly, the passive coupling subassembly includes: PCB board, light electric chip are to eka silicon platform and light electric chip, the terminal surface of first plus lens and second plus lens is 40 inclined planes, 40 the reflectance coating has been plated on the inclined plane. The passive alignment of grating coupler can be realized to the silicon structure platform that the rational design light path is accurate with the design, greatly reduced the device cost.