The utility model discloses a convenient siphon drainage system, include: siphon unit, liquid level indicating units and air exhaust device, the siphon unit includes inlet tube, first connecting pipe, second connecting pipe and outlet pipe, the inlet tube with the outlet pipe passes through first connecting pipe is connected, the top of first connecting pipe is provided with the apical pore, the second connecting pipe passes through the apical pore with first connecting pipe is connected, liquid level indicating units includes check valve, the person in charge, liquid level calibrated scale, be responsible for with the second connecting pipe other end is connected, the check valve sets up the person in charge is close to the one end of second connecting pipe, the liquid level calibrated scale sets up the person in charge keeps away from the one end of second connecting pipe, the person in charge keeps away from the one end of second connecting pipe is still including bleeding the end, air exhaust device links to each other with it. The utility model discloses a disconnect -type structure can be used in a flexible way according to the connecting pipe of the different length of the on -the -spot actual conditions selection of engineering.