The utility model provides a drilling fluid flow detection device, its entry flow detection device probe detects drilling fluid inlet pipe's rate of flow of fluid, export flow detection device probe detects drilling fluid export pipeline's rate of flow of fluid, the height of drilling fluid export pipeline liquid level is measured to the ultrasonic ranging device, entry flow data gathers processing module and carries out signal processing with drilling fluid inlet pipe's rate of flow of fluid data, export flow data gathers processing module and carries out signal processing with drilling fluid export pipeline's the rate of flow of fluid data and the height data of drilling fluid export pipeline liquid level, logging appearance data acquisition system is with the signal transmission down -hole troublesome condition analytic system in the pit of their output, down -hole troublesome condition analytic system carries out data storage in the pit, show, the playback, the analysis. This drilling fluid flow detection device can realize the real -time quantitative determination and the analysis of drilling fluid entry and export, has apparent economic benefits and social to oil and gas exploration.