The invention relates to an MZ-type buried scraper sludge conveyor and an MZ-type buried scraper sludge conveying method thereof. The MZ-type buried scraper sludge conveyor mainly consists of a tail part, a lower horizontal section, a lower bending section, a vertical section, an upper bending section, an upper horizontal section and a head part, wherein the lower horizontal section, the vertical section and cross section of a shell of the upper horizontal section are of a 'TU'-shaped (a Chinese character) structure, a scraper chain is arranged in the shell, a double row roller chain of the scraper chain is arranged on left and right shoulders of the shell, and a scraper of the scraper chain is arranged in a groove of the shell and keeps a distance with the groove. The MZ-type buried scraper sludge conveyor and the method thereof which are provided by the invention have the advantages that the double row roller chain, an external scraper and a convex shell are arranged, and sludge is avoided from being directly contacted with the roller chain, so that corrosion of the sludge on the roller chain is reduced, and difficult material reverting and discharging caused by the fact that the sludge is bonded on the scraper chain can be avoided.