The invention discloses an explosive and powder modeling powder free-running property testing method. The method is designed to solve the problems that a test on the free-running property of explosive and powder modeling powder in the prior art is not high enough in precision, and the application requirement cannot be met. The explosive and powder modeling powder free-running property testing method is characterized in that a testing device and a sample need to be stored for more than 2 h in the environment of 15 DEG C to 25 DEG C before a test; a funnel inserting plate (2) is inserted to block a funnel flow-out opening; the mass of a weighing standard cup (9) is recorded as m0, a standard cup of explosive and powder modeling powder samples is weighed out and is striken off with a scraper and weighed, total mass is recorded as mt, and therefore the mass of the samples is m=mt-m0. The samples are carefully poured into a funnel (3). The funnel inserting plate (2) is pulled out, and meanwhile timing is started. When the samples exactly flow out of a discharging opening, timing is stopped, consumed time is recorded as t, and the free-running rate of explosives and powders is calculated accordingly. Compared with an existing testing technology, the method is higher in testing precision and can meet the application requirement.