The invention provides an engine combustion flow field speed measuring device and method based on flame radiation characteristics. The measuring device comprises a light condensation unit, a photovoltaic conversion unit, a data acquisition system and a data processing unit, wherein the light condensation unit is located between an engine combustion flow field to be measured and the photovoltaic conversion unit and comprises two convex lenses which are arranged in parallel in the axial direction of the flow field, the photovoltaic conversion unit comprises two photoelectric converters with receiving ports on the center lines of the two lenses, and the data processing unit is used for processing data stored in the data acquisition system so that the speed of the combustion flow field can be obtained. According to the engine combustion flow field speed measuring device and method based on the flame radiation characteristics, the flame radiation characteristics serve as the basis, flame radiation optical pulsation signals serve as random signals of cross-correlation analysis to achieve cross-correlation speed measurement, and the engine combustion flow field speed measuring device and method overcome the defects that according to a contact type measuring method, a flow field is disturbed easily, and combustion is influenced, and have the advantages of being simple in structure, free of contact and high in sensitivity.