The invention discloses an inner cooling water valve-entrance temperature high protection method for a valve cooling system of a converter valve. A valve cooling control protection system reads a DC current real-time value from a pole control device and simultaneously reads inner cooling water valve-entrance real-time temperature values from three inner cooling water valve-entrance temperature sensors; if the three temperature sensors all break down, the valve cooling control protection system sends out a tripping command to lock a DC power transmission system, or else, selects a maximum temperature value as the inner cooling water valve-entrance real-time temperature value, calculates a real-time junction temperature of a converter valve thyristor according to the inner cooling water valve-entrance temperature and the DC current value, compares a junction temperature value of the thyristor with a junction temperature limit value, sends out an alarm signal when the junction temperature of the thyristor reaches an alarm value, sends out the tripping command to lock the DC power transmission system when the junction temperature of the thyristor reaches the junction temperature limit value. The method disclosed by the invention is good in coordinated control performance and can adapt to the converter valve of the DC power transmission system under the conditions of various voltage grades and DC loads.