Disclosed are a grouting pipe for a miscellaneous fill stratum and a construction method. The grouting pipe is mainly composed of an external grouting pipe body, an internal grouting pipe body, a slurry stop plug, a segment spacer ring and a sealing plug, wherein one end of the external grouting pipe body and the surface of the pipe body are provided with grouting holes; the internal grouting pipe body is fixed to the segment spacer ring through the slurry stop plug; a grouting hole is formed in the top end of the internal grouting pipe body, and grouting holes are evenly distributed around one end of the pipe body; the bottom end of the internal grouting pipe body is connected with a grouting machine through a mortar conveying pipe; the segment spacer ring is fixed to the inner wall of the external grouting pipe body. The grouting pipe has the characteristics of low pressure, high frequency, segmentation and quick grouting, thereby accurately controlling the grouting pressure and grouting parameters for the complex situations of miscellaneous fill stratums containing large gravel or building rubbish; a grouting curtain within a certain range is formed in the stratum, greening vegetation over the stratum is not affected, and the purpose of effectively reinforcing the miscellaneous fill stratum is achieved. The grouting pipe is convenient to use, conducts grouting quickly and can be widely applied to miscellaneous fill stratums needing reinforcing.