Abstract: The complex flow behavior of gas-liquid two-phase flow in the oil and gas gathering pipelines, especially the annular flow in elbows, is extremely prone to intensify the pipeline corrosion and damage. Therefore, the annular flow experiment in horizontal elbows was carried out. On this basis, the phase distribution, the flow velocity of liquid film and the pressure variation laws at the apparent gas velocity of 20-35 m/s and apparent liquid velocity of 0.20-0.35 m/s were analyzed. Then, the phase distribution, pressure distribution and velocity distribution in the horizontal elbows were studied by numerical simulation to supplement the law of flow characteristics of annular flow in elbows. As the results indicate, the liquid film at the bottom and outer side of the elbow is thicker than that at the top and inner side of the elbows, with the difference between that on both sides of the elbows varying increasingly at the places closer to the center of the elbows. Besides, the increase of apparent gas velocity and the decrease of liquid velocity may lead to the uniform distribution trend of liquid film. The pressure on the inner side of the elbows is lower than that on the outer side of the elbows. Moreover, under the influence of secondary flow, the maximum pressure at the center section of 90° elbows is greater than that at the inlet at low gas velocity. Generally, the research results could provide theoretical basis for the study on erosion mechanism and the design and protection of elbows.