Sole capable of adjusting hardness and shoe

The invention discloses a hardness-adjustable sole which comprises a sole body, the sole body is of a hollow structure, a direct-current power source, a solenoid and a permanent magnet are arranged in the sole body, the solenoid is of a hollow structure and is connected with the direct-current power source to form a closed loop, and the permanent magnet is connected with the sole body. The magnetic field direction generated after the solenoid is electrified is opposite to that of the permanent magnet. When the direct-current power supply is turned on, the solenoids generate magnetism and repel the permanent magnets, the foot of a human body is subjected to resistance when applying downward pressure to the sole body, the sole body is not prone to bounce off due to the effect of the Lenz's law when a user lifts the foot, the sole body is in a high-hardness state at the moment, and the sole is suitable for use places where the requirement for the sole is high. When the direct-current power supply is turned off,