Lying lengthened type multi-connection-rod stretching mechanism

The utility model relates to a lying lengthened type multi-connection-rod stretching mechanism. The lying lengthened type multi-connection-rod stretching mechanism comprises a base, a connection rod retractable assembly and a backrest plate assembly, wherein the connection rod retractable assembly comprises a front vertical rod, a top beam, a right connection rod set and a left connection rod set; an elbow plate is hinged between the end part of the front vertical rod and the top beam; a leg lifting assembly is hinged with the end parts of the right connection rod set and the left connection rod set; the leg lifting assembly comprises an elbow yoke plate hinged with the left connection rod set, a straight connection rod connected with one end of the elbow yoke plate, a first connection rod hinged with the right connection rod set, a second connection rod hinged with the first connection rod, a third connection rod connected with the end part of the second connection rod and a leg supporting plate; the end par