Abstract: A method for extracting road capacity based on traffic big data includes the following steps: selecting a specific traffic flow model; reading massive road lane traffic flow parameters; calibrating a model parameter of the selected traffic flow model by using the road lane traffic flow parameters read in the previous step; and fitting the calibrated model parameter to obtain a fitted traffic flow model. The present invention solves the problems that traditional methods for traffic capacity calibration have a heavy workload, inadequate samples and unreliable results due to their reliance on manual information acquisition, thereby providing support for automatic, long-term, large-scale and precise acquisition of the capacity.