The invention relates to an automotive fuel assisted heating system and a control method thereof with an aim to mainly solve problems about discomfort of a cockpit under cold winter environment and low efficiency of cold start of an engine. A fuel assisted heater heats the cockpit and the engine respectively in the cold starting stage of a vehicle to enable the cockpit and the engine to be heated rapidly; the main technical feature is that a fuel assisted heating cycle coolant is controlled to run in a nucleate boiling regime, and heating efficiency is improved. The automotive fuel assisted heating system has the advantages that the fuel assisted heating cycle coolant is controlled to be the nucleate boiling regime, heat exchange rate is enabled to be optimized, pump loss is reduced, heat of the assisted heater is enabled to be more uniform, and damage brought to the assisted heater due to heat unevenness is reduced.