Disclosed are a method for estimating a load current of a power supply, and a USB-type converter. The method includes steps described below. After an input port of a USB connection line is connected to the power supply and an output port of the USB connection line is connected to a load, the power supply supplies power to the load through the USB connection line to obtain an initial load current value; an actual voltage value of the input port is detected, when the actual voltage value of the input port is less than a preset voltage value, the initial load current value is adjusted until the actual voltage value of the input port corresponding to an adjusted load current value is not less than the preset voltage value, and the adjusted load current value is output as a load current value of the power supply.