The invention relates to a drilling winch disc brake control method and control system. When a winch main motor normally operates, a PLC outputs a dry contact signal to enable the function of an electronic brake crank to be failed; when a disc brake needs to be used, the PLC sends a signal to enable the winch main motor to stop rotating, and the dry contact signal is unblocked to enable the function of the electronic brake to be recovered; when a winch needs to be suspended, a parking rotary knob is rotated to enable a parking valve to be switched off, and safety tongs apply the brake; the PLC outputs the dry contact signal to enable the winch main motor to stop rotating; when emergency braking is performed, an emergency braking button is pressed down to enable an emergency braking valve to be switched off, and the system is in an emergency braking state; the PLC outputs the dry contact signal to enable the winch main motor to stop rotating. According to the method and system, linkage control is performed on operation of the disc brake and the drilling winch main motor, equipment damage caused by misoperation is fundamentally prevented, and occurrence of injury accidents is completely eradicated; operation is easy, use is convenient and sensitive, and the operation safety of the drilling winch disc brake is greatly improved.