A mechanical sand control liner or composite rigid seam pipe used for the oil well underground sand control is provided. The utility model comprises a base pipe, a spacer ring, a gland, and a coupling; wherein the a thread is arranged at both ends of the base pipe, while the connecting bolt at one end of the base pipe is provided with the coupling; and the wall of the base pipe is provided with a sieve pore. The utility model is characterized in that the outer wall of the base pipe with the pore is sleeved with a spacer ring set, wherein a clearance is positioned between the spacer rings; and the gland is tightly arranged at both ends of the spacer ring and welded on the base pipe. The utility model has the effects of that the composite rigid seam pipe is supported by the base pipe in the middle, and the spacer ring is sleeved on the base pipe, and the entire strength of the pipe cylinder is not lower than that of the standard pipe cylinder, thus adapting to the special structure of oil well and sidetracked hole shaft and capable of improving sand protection effect; and in addition, the entire strength is sufficient to resist the extrusion of the stratum, thus prolonging the service life; and the block resistant capacity is strong, and two echelon cross section spaces have self cleaning function, so capable of avoiding the sand particles from being blocked in the clearance to build u the seam pipe, prolonging the usage period and convenient for backflushing; and the clearance density is high, and the penetration area is large, thus capable of realizing highly efficient sand control.