The invention discloses a corner post-free carriage for a railway vehicle, which comprises a floor (1), side wall boards (2) positioned on two sides of the floor (1), and end sheathings (3) positioned at two ends of the floor (1); the bottom sides of the side wall boards are bent upwards, and the bent parts (2) are subjected to assembly welding with corresponding sides of the floor (1) in a lapped way; the two ends of the floor (1) are bent upwards to form upper flanges which are lapped with the bottoms of the corresponding end sheathings (3) and are fixed by welding; and two sides of the endsheathings (3) are deformed and bent to form right-angle flanges which are subjected to assembly welding with corresponding ends of the side wall boards (2) in a lapped way. Compared with the prior art, the corner post-free carriage has simple structure, easy processing and manufacturing, less working procedures, low manufacturing cost, and light total weight of the whole, improves the carrying capacity, and contributes to reducing energy consumption of locomotives to save the energy.