The invention provides an online viscous material continuous heating device. The online viscous material continuous heating device comprises a controller, a buffer tank, a first heat exchanger, a second heat exchanger, a stirring tank, a first heater and a second heater, wherein the buffer tank, the first heat exchanger, the stirring tank and the second heat exchanger are sequentially communicated with one another through a pipeline, the first heat exchanger is connected with the first heater, the second heat exchanger is connected with the second heater, and the controller is connected with the pipeline. Compared with the prior art, uniformity in heating can be realized, the heating effect can be improved, the heating time can be shortened, the energy consumption can be reduced, and the production efficiency can be improved.