The invention relates to a transmission system fault detection method and device, a computer storage medium and equipment. According to a direct current rising speed and direct current voltage magnitudes of two ends of a conversion equivalent capacitor, a system inductance in the time of failure is obtained, according to a condition that the system inductance is equal to a sum of inductance in an overall equivalent circuit, a line fault inductance between a preset detection point for installing a relay protection device in the overall equivalent circuit and a fault point in the time of failure is obtained, through comparing the line fault inductance and preset setting inductance, a fault area of a flexible direct current transmission system relative to the preset detection point can be accurately determined, the accuracy of fault detection is improved, and the safety of the flexible direct current transmission system is improved.