The present invention provides a premixed charge compression ignition engine and control system (10), which can effectively trigger combustion and maintain stable combustion by means of compression ignition, while achieving extremely low nitrogen oxide emissions, good overall efficiency and Acceptable combustion noise and cylinder pressure. The engine and control system (10) of the present invention can effectively control the combustion process by controlling certain control variables of temperature control, pressure control, mixture self-ignitability control and equivalence ratio control, that is, the time of combustion initiation, the combustion rate , duration of combustion and / or completeness of combustion. The combustion control system (10) provides active feedback control of combustion and includes a sensor for detecting engine operating conditions representative of a combustion process, such as ignition of combustion, and generating a corresponding engine operating condition signal (18) , such as the pressure sensor (16).