There are abundant resources of heavy hydrocarbons worldwide, and their utilization is becoming more widespread as time progresses. The present paper proposes a process that combines coke gasification and heavy hydrocarbon pyrolysis, producing synthesis gas and light olefins. Simulation studies on the process are carried out by using Aspen Plus. The results show that the temperature of the gasification-pyrolysis can be controlled by changing the feed rate of O-2 and steam. In addition, the coke jam problem can be solved by increasing the gasification-pyrolysis temperature or residence time. The maximum amount of light olefins can be acquired by controlling the gasification-pyrolysis residence time. More than 37 wt% heavy hydrocarbons are changed to synthesis gas with more than 15 wt% changed to light olefins in the case studied.