The invention discloses a sleeve type fuel assembly and a supercritical water cooled reactor. The sleeve type fuel assembly sequentially comprises an inner pipe and an outer pipe from inside to outside in the radial direction; an area surrounded by the inner pipe is an inner area; an inner zone fuel rod is arranged in the inner area; an area between the outer pipe and the inner pipe is an outer area; an outer area fuel rod is arranged in the outer area, the upper portion of the outer pipe is of an open structure, the lower portion of the outer pipe is of a closed structure, the two ends of theinner pipe are of open structures; coolant flows in the outer area from top to bottom, and flows in the inner area from bottom to top, and the fuel enrichment degree of the inner area fuel rod is higher than that of the outer area fuel rod. The sleeve type fuel assembly can solve the problem of complication of a fuel assembly and a reactor core structure due to the adoption of a water slowing-down rod and coolant multi-flow design technology in the prior art, and has the advantages of improving the reactor core coolant flow rate, enhancing heat transfer and reducing fuel cladding temperature.