The invention discloses a 660 MW supercritical unit no-furnace water circulation pump boiler pipe flushing system, and belongs to the technical field of boiler pipe flushing. Sundries clearing can becarried out on a part of a steam conveying pipeline close to a boiler without stopping steam supply of the steam conveying pipeline to a steam turbine. The system comprises a boiler, a steam inlet pipe, a main pipe, a steam outlet pipe, a side pipe, a dirt removal pipe and a dirt cleaner, wherein a left pipe opening of the main pipe comprises an upper left pipe opening and a lower left pipe opening which are arranged in a forked manner; a right pipe opening of the main pipe comprises an upper right pipe opening and a lower right pipe opening which are arranged in a forked manner; the left endof the side pipe is bent downwards and rightwards in an arc-shaped manner to form a left bending section pipe of the side pipe; the right end of the side pipe is bent downwards and leftwards in an arc-shaped manner to form a right bent section pipe of the side pipe; one end of the steam inlet pipe is in butt joint connection with the lower left pipe opening of the main pipe; and the other end of the steam inlet pipe is in butt joint connection with a steam outlet of the boiler.