The temperature-related evolution law of friction and wear behaviours of copper-based powder metallurgy friction block on forged steel brake disc under extreme braking conditions are studied. The results indicate that the friction and wear behaviours of the friction block have certain randomness with temperature rise, but the overall trend is definite. The friction coefficient at room temperature is 0.33, starts to rise when the temperature exceeds 170 degrees C, reaches its maximum value of 0.43 at 240 degrees C and remains stable until 400 degrees C. After that, the friction coeffi-cient starts to decrease significantly. The wear rate starts to increase significantly when the temperature reaches about 100 degrees C. When the temperature reaches 500 degrees C, the wear rate increases by an order of magnitude compared with that at room temperature. When the temperature rises from room temperature to nearly 500 degrees C, the wear mechanism gradually changes from abrasive wear to oxidative wear, and finally to adhesive wear.