The utility model discloses a multifunctional ball valve which comprises a valve body. A valve cavity is formed in the valve body, and a ball body used as a valve element is arranged in the valve cavity. The ball body is a ball body used for a two-way valve or a ball body for a three-way valve and detachably arranged in the valve cavity as required. A first fluid channel communicated with the valve cavity is arranged on the valve body, wherein a stopper is detachably arranged on the first fluid channel in a sealed mode to enable the multifunctional ball valve to be converted into a two-way ball valve, or a pipe connector is detachably arranged on the first fluid channel in a sealed mode to enable the multifunctional ball valve to be converted into a three-way ball valve. A second fluid channel and a third fluid channel which are used for being correspondingly communicated with the first fluid channel respectively are further arranged on the valve body, wherein on-off of the second fluid channel and on-off of the third fluid channel are controlled by the ball body for the two-way valve, or the second fluid channel and the third fluid channel are controlled by the ball body for the three-way valve. By installing the stopper or the pipe connector on the first fluid channel and meanwhile correspondingly replacing different ball bodies, the multifunctional ball valve can be converted into the two-way valve or the three-way valve, the conversion speed is high, the application range is wide, and the purchasing, installing and maintaining cost can be effectively reduced.