The present disclosure relates to a crude oil parameter detection device, which includes a liquid cavity constituted by a first housing, a flow measurement cavity constituted by a second housing, a detection cavity constituted by a third housing, and a processing module; the flow measurement cavity is in-built in the liquid cavity; the first housing includes a first liquid inlet and a first liquid outlet; the second housing includes a second liquid inlet and a second liquid outlet; the second liquid outlet is in communication with the first liquid outlet through a liquid outlet pipeline; a float assembly is in-built in the flow measurement cavity, which includes a float and a float connection rod integrally connected with the float, and an end of the float connection rod is connected to a detection part; the detection cavity at least internally comprises a position detection module; the position detection module detects a position of the detection part at the end of the float connection rod to obtain a float height detection signal; and the processing module calculates a flow rate of measured crude oil according to the float height detection signal. The present disclosure can safely meter the crude oil flow rate of a crude oil transport pipeline and meet the accuracy of metering the crude oil.