The invention provides a rotary four-way reversing valve with low pressure drop and low leakage, comprising a valve body and a valve core arranged in the valve body through bearings. The valve body comprises a low-pressure exhaust tube, a high-pressure air inlet tube, a condenser tube and an evaporating tube. The valve core is slantingly divided by a U-shaped seal ring with a spring into a high-pressure chamber and a low-pressure chamber that are not communicated with each other. The valve core comprises a through hole arranged in the high-pressure chamber and aligned with the high-pressure air inlet tube of the valve body and an opening aligned with the condenser tube or the evaporating tube, an opening arranged in the low-pressure chamber and always aligned with the low-pressure exhaust tube and an opening aligned with the condenser tube or the evaporating tube.

A gas circulation apparatus is applied to a pneumatic apparatus including a solenoid valve apparatus and a cylinder apparatus, and is connected in series between the solenoid valve apparatus and the cylinder apparatus. The gas circulation apparatus includes a valve core structure, a first circulation cavity, and a second circulation cavity. The valve core structure is configured to move in a first direction, so that compressed gas discharged from a first cylinder cavity of the cylinder apparatus and passing through the solenoid valve apparatus is collected and stored by the first circulation cavity, and a second cylinder cavity of the cylinder apparatus is supplied with compressed gas stored in the second circulation cavity together with the compressed gas supplied from the solenoid valve apparatus.