The utility model discloses a double-horn orifice measurement orifice plate of a natural gas single well gas-liquid two-phase on-line measurement instrument, which is applied to the natural gas single well gas-liquid on-line measurement in an oil field. A steel ring is annular, a throttle plate is arranged at the middle of the annular steel ring and is provided with a throttle hole at the center, the throttle hole comprises an inlet end horn orifice and an outlet end horn orifice, the inlet end horn orifice and the outlet end horn orifice 7 are taper orifices having centers lines on one same straight line, and the inlet end horn orifice and the outlet end horn orifice are communicated. The double-horn orifice measurement orifice plate has the effect of solving the problem of increased measurement errors of an orifice plate differential pressure type natural gas gas-liquid two-phase flowmeter, which is caused by dirt accumulation in front of the orifice plate during the measurement, and further has the effect of realizing orifice plate self-cleaning through scouring by dint of the fluid own flowing speed.