The invention relates to an alloy pipe containing 18-24% of Mn and a manufacturing method thereof. The alloy pipe comprises: 0.002-0.2% of C, 18-24% of Mn, 0-4% of Si, 0-5% of Al, no more than 0.015% of P, no more than 0.01% of S, no more than 0.008% of N, or one or more of 1-6% of Cr, 0.1-0.5% of Cu, 0.01-0.6% of Nb, 0.01-0.1% of Ti and 0.01-0.3% of V, and balance of Fe. The manufacturing method comprises the following steps: casting the raw materials by vacuum melting, carrying out homogenizing annealing and hot-rolling on the casted materials so as to be manufactured into steel plates or bars; carrying out resistance-welding or hot-rolling on the steel plates or balls so as to be manufactured into pipe blanks; carrying out solid solution treatment and ageing treatment on the pipe blanks, wherein the obtained product has a uniform elongation percentage no less than 50% and a yield strength of 300-400MPa; and carrying out dilatational strain of 30% on the pipe blanks, wherein the obtained product has the uniform elongation percentage no less than 20%, the yield strength of 560-760MPa and the yield ratio of 0.62-0.80.