The disclosure discloses a coupler assembly and a straddle type rail train with the same. The coupler assembly includes a mounting base, a buffering mechanism, a folding mechanism, and a coupler head, one end of the buffering mechanism is interconnected movably with the mounting base, the other end of the buffering mechanism is provided with a pull rod, the pull rod is provided with a limiting portion, one end of the folding mechanism is interconnected movably with the pull rod, the folding mechanism is provided with a locking part, the locking part movably cooperates with the limiting portion to lock or release the pull rod, and the pull rod is fixed at a stretching position when the limiting portion is locked by the locking part, and is movable between a folding position and the stretching position when the limiting portion is released by the locking part; and one end of the coupler head is interconnected with the other end of the folding mechanism.