The present invention provides a drip irrigation pipe, which comprises a pipe body. The pipe body is formed with a main pipe region and an irrigation region. The main pipe region is formed with a main channel, and the irrigation region is configured with a plurality of irrigation units communicated and cascaded with each other. One end of the irrigation unit is provided with a communication portion communicated with the main channel. The irrigation unit has an irrigation channel communicated with the communication portion and at least one narrow portion. The portion of the irrigation channel adjacent to the narrow portion is formed as a neck portion. The water inlet of the irrigation unit at the neck portion is formed as an accelerating section with gradually reduced dimensions. The water outlet directly communicated with the neck portion is formed as a decelerating section with gradually increased dimensions. An outer water outlet exposed from the pipe body is configured near the intersection of the neck portion and the decelerating section. With the cooperation of the accelerating section, the neck portion and the decelerating section, the irrigation channel is not required to be designed as a conventional curved, long-span and narrow shape, which may prevent the clogging of the drip irrigation pipe to increase the service life, and may cause the Venturi effect during water flowing to provide the negative pressure effect for inhibiting the water dispensing amount of the outer water outlet and thus achieving the drip irrigation effect with small water dispensing amount.本發明係一種滴灌管,其包含一管體,該管體上形成一主管區及一澆灌區,在該主管區內形成一主流道,以及在該澆灌區內設置複數連通串接的澆灌單元,所述澆灌單元一端設有連通該主流道的連通部,以及所述澆灌單元具有一連通連通部的澆灌流道與至少一狹窄部,澆灌流道於鄰接狹窄部處形成頸縮部,且澆灌單元於頸縮部的入水端形成一尺寸漸縮的增速段,頸縮部直通的出水端形成一尺寸漸擴的減速段,並於頸縮部與減速段交界附近設置一外露於管體的外出水口,增速段、頸縮部與減速段的配合,使澆灌流道因此可以不必設計成傳統曲折、長距、狹窄的形狀,可防止滴灌管堵塞以提高使用壽命,水流通過時可產生文丘里效應,其負壓作用可抑制外出水口的出水量,達到小量出水的滴灌效果。1‧‧‧管體10‧‧‧主管區11‧‧‧主流道21‧‧‧澆灌單元22‧‧‧連通部23‧‧‧澆灌流道24‧‧‧狹窄部25‧‧‧頸縮部26‧‧‧增速段27‧‧‧外出水口28‧‧‧減速段
