The invention discloses a novel art knife. The novel art knife comprises a shell. A slidable knife rest is arranged in the shell. An opening allowing a blade to extend and retract is formed in the head of the shell. The novel art knife is characterized in that the knife rest is provided with a lock block for locking the blade; the shell is correspondingly provided with a blade replacement switch for unlocking the lock block; a standby blade slot is formed in the position, corresponding to the completely retracting blade of the knife rest, of the shell; a fixing block which corresponds to a clamping opening in a standby blade and is used for fixing the standby blade is arranged on the standby blade slot; a standby blade cover is arranged on the outer side of the standby blade slot; and a leaf spring abutting against the standby blade is arranged on the inner wall of the standby blade cover, and thus the standby blade has the tendency of keeping inwards abutting against the knife rest to achieve continuous use. The novel art knife is simple in structure and convenient to assemble, has the blade quick-replacement function and can be used continuously, and gear positioning can be achieved according to the requirement of blade extension or retraction length in use.