The invention provides a direct current power adjustment and control method for inhibiting the alternating current-direct current coupling weakening stability, which comprises the following steps that (1), an extra-high voltage direct current transmission end alternating current-direct current series-parallel power grid simulation model is established; (2), the transient state stability and the electromechanical oscillation damping characteristic of a transmission end power grid under large disturbance impact are evaluated; (3), a key factor of the alternating current-direct current coupling weakening stability is determined; (4), a power adjustment controller is subjected to direct current configuration; and (5), an effect of power adjustment and control is verified. With the adoption of the method, by using the quick adjustment and control characteristic of extra-high voltage direct current power, an adverse effect of an intercoupling function of an alternating current-direct current system during sharp fluctuation of the electrical quantity after large disturbance on the stability of the power grid is inhibited, and the safe and stable operation capability and the extra-high voltage direct current high-capacity stable power transmission capability of the extra-high voltage direct current transmission end power grid are improved.