A lamp mounting assembly mounted on a roof (10) comprises a lamp main body (20), a mounting frame (30) fixedly connected to the lamp main body (20) and used for fixing the lamp main body (20) to the roof (10), a front-side frame (40) detachably connected to and covering the mounting frame (30), and a pull rope assembly (50) connected to the mounting frame (30) and used for fixing the mounting frame (30) to the roof (10). The length of the pull rope assembly (50) can be adjusted. The lamp main body (20) is fixed to the roof (10) by means of the mounting frame (30), and the detachable front-sideframe (40) used for covering the mounting frame (30) is added on the mounting frame (30), so that the mounting frame (30) is not exposed; and on the premise that the mounting frame (30) does not needto be replaced, the front-side frame (40) can be of any shape and can be replaced as required, and the lamp can be maintained by only detaching the front-side frame (40), and accordingly, the situation in the prior art in which the lamp can be maintained by detaching the mounting frame (30) and the front-side frame (40) together is changed. By means of the pull rope assembly (50) of an adjustablelength, the relative positions among the mounting frame (30), the lamp main body (20) and the roof (10) can be adjusted, and assembly requirements in a variety of mounting scenarios can be further satisfied.