An oxidizer injector for a motor of a hybrid rocket engine, comprising: a body having a feed passage as well as a first runner assembly and a second runner assembly which communicate with the feed passage, the feed passage having an axis, the first runner assembly and the second runner assembly being sequentially arranged along the axis, the first runner assembly having a plurality of forward runners, and the second runner assembly having a plurality of reverse runners, each of the forward runners being disposed along a forward running direction (U'), and each of the reverse runners being disposed along a reverse running direction (U"), one of the forward running directions (U') being defined as a first forward running direction (U'), and one of the reverse running directions (U") being defined as a first reverse running direction (U"), the first forward running direction (U') and the first reverse running direction (U") extending and a position of intersection of the first forward running direction (U') and the first reverse running direction (U") in the direction of axis _being an intersection point, and an extending direction of the intersection point to the axis being a central axis, the first forward runner being located at one side of the central axis of the body, and the first reverse runner being located at another side of the central axis of the body, a forward angle (θ1) being formed between the first forward running direction (U') and the central axis, a reverse angle (θ2) being formed between the first reverse running direction (U") and the central axis, and an absolute value of the forward angle (θ1) and an absolute value of the reverse angle (θ2) being equal, wherein the body has an inner wall surface facing the feed passage, an injection angle (θ3) is formed between each of the forward runners and the inner wall surface, as well as between each of the reverse runners and the inner wall surface, and the injection angles (θ3) are located on a side close to the combustion chamber when the oxidizer injector is mounted in the motor of the hybrid rocket engine, wherein each of the forward runners is configured to introduce a forward swirl and each of the reverse runners is configured to introduce a reverse swirl, wherein the injection angles (θ3) are equal. a body having a feed passage as well as a first runner assembly and a second runner assembly which communicate with the feed passage, the feed passage having an axis, the first runner assembly and the second runner assembly being sequentially arranged along the axis, the first runner assembly having a plurality of forward runners, and the second runner assembly having a plurality of reverse runners, each of the forward runners being disposed along a forward running direction (U'), and each of the reverse runners being disposed along a reverse running direction (U"), one of the forward running directions (U') being defined as a first forward running direction (U'), and one of the reverse running directions (U") being defined as a first reverse running direction (U"), the first forward running direction (U') and the first reverse running direction (U") extending and a position of intersection of the first forward running direction (U') and the first reverse running direction (U") in the direction of axis _being an intersection point, and an extending direction of the intersection point to the axis being a central axis, the first forward runner being located at one side of the central axis of the body, and the first reverse runner being located at another side of the central axis of the body, a forward angle (θ1) being formed between the first forward running direction (U') and the central axis, a reverse angle (θ2) being formed between the first reverse running direction (U") and the central axis, and an absolute value of the forward angle (θ1) and an absolute value of the reverse angle (θ2) being equal, wherein the body has an inner wall surface facing the feed passage, an injection angle (θ3) is formed between each of the forward runners and the inner wall surface, as well as between each of the reverse runners and the inner wall surface, and the injection angles (θ3) are located on a side close to the combustion chamber when the oxidizer injector is mounted in the motor of the hybrid rocket engine, wherein each of the forward runners is configured to introduce a forward swirl and each of the reverse runners is configured to introduce a reverse swirl, wherein the injection angles (θ3) are equal.