The utility model provides an insert type bidirectional pressure-reducing valve. The insert type bidirectional pressure-reducing valve comprises a housing with a chamber, a valve core located inside the chamber and a biasing device making the valve core move towards a closing position. The housing comprises the chamber, a first outlet/inlet and a second outlet/inlet. Each outlet/inlet is connected with the chamber. The chamber comprises a central part with a first diameter and a diameter-reducing end part with a second diameter smaller than the first diameter. The valve core can move inside the chamber relative to the housing. The valve core comprises a smaller diameter part accommodated in the diameter-reducing end part and a larger diameter part accommodated in the central part of the chamber. The valve core comprises a pathway communicated with the first outlet/inlet and a radial hole extending from the pathway and passing through the valve core. The biasing device makes the valve core move towards the closing position. Flowing fluids passing through the radial hole between the pathway and the second outlet/inlet are blocked on the closing position. When the biasing force from the biasing device is overcome, the valve core then moves to an opening position. On the opening position, the smaller diameter part of the valve core moves towards the central part of the chamber. The fluids passing through the radial hole between the pathway and the second outlet/inlet are then no longer blocked.