The present invention provides a coronary artery load detection system and method, and the method includes: (S1) obtaining the cross-sectional area of a reference cavity, and separately obtaining voltage values of a primary device at a location corresponding to the cross-sectional area of the reference cavity in a low frequency state and a high frequency state (S2) separately obtaining voltage values of the primary device at the location of a bottom end or a top end of a to-be-detected object in the low frequency state and the high frequency state under the same current (S3) driving the primary device to move at a constant speed, and obtaining a voltage value of the primary device during the movement in the low frequency state under the same current and (S4) obtaining the cross-sectional area of each location of the to-be-detected object according to a preset fixed current value, the cross-sectional area of the cavity, and the obtained voltage values. According to the present invention, a voltage value of each location of the to-be-detected object is obtained in a frequency conversion mode, so that the sectional area of each location of the to-be-detected object is obtained by means of parsing and parameters such as a plaque parameter and an FFR of each location of the to-be-detected object are obtained according to the sectional area, thereby greatly simplifying an operation and processing process and reducing the detection costs.