The invention discloses a coupling system of a hydrogenation unit and a light-component removal tower of reforming full-fraction liquid product. The coupling system comprises the hydrogenation unit and the light-component removal tower. The coupling relationship between the hydrogenation unit and the light-component removal tower refers to that a heat exchanger A is arranged on a hydrogenated product removal pipeline and a heat exchanger B is arranged on a tower bottom heavy component removal pipeline, wherein the hydrogenated product removal pipeline is communicated with the heat exchanger Aand is further communicated with the heat exchanger B through the other pipeline, and finally is communicated with the light-component removal tower through a feeding pipeline of the light-component removal tower. On the basis of the prior art, the coupling system solves the problem about influence on operation of the light-component removal tower from temperature rise of the hydrogenation unit and facilitates stable running of the devices while prolonging running period of the devices.