The Huangshan Pi uses the raise_wrist routine, directly burning and downloading. I simply measured the current through the Type-C port and found that when inserting the SD card, the current increases by about 20mA. How can this be eliminated? Looking at the schematic, PA_26 switches the power supply for the SD card and touch, and it is pulled low during sleep, but the increased current from the SD card remains.
PA26 indeed controls the power supply of the SD card. After pulling it low during sleep, you can use a multimeter to actually measure the corresponding points, or measure the points on the TF card, to see if there is still power. If there is still power, then you need to question whether PA26 has actually been successfully pulled low. Additionally, it could be that the pins corresponding to the SD card are leaking current. After entering sleep, also handle those SD card pins synchronously to prevent leakage.