The invention discloses a bottom door opening and closing mechanism for a railway funnel vehicle. The bottom door opening and closing mechanism comprises a bottom door, a vehicle body underframe and a vehicle body side wall. The bottom door opening and closing mechanism further comprises a first end transmission device, a second end transmission device, a transmission shaft assembly, a central driving device, a bottom door opening device and a top door closing device. By operating an abutting pressure device on the ground, the bottom door opening device is opened to discharge goods; and the bottom door is closed by abutting against the top door closing device downwards. A locking function is achieved through the end transmission devices, the central driving device and a connecting pin shaft of the bottom door. According to the bottom door opening and closing mechanism, a complex wind-driven or manual control bottom door opening and closing system is omitted, and the loading weight of the vehicle is effectively improved.