The invention relates to the technical field of engineering machines, and discloses a hydraulic valve, a hydraulic system and an engineering machine, wherein the hydraulic valve comprises a valve body(1) provided with a valve cavity, a valve element (2) is arranged in the valve cavity, the valve cavity is sequentially divided into a pressure output cavity (7), an intermediate cavity (5) and two or more pressure input cavities (4) through the valve element (2), and the valve body (1) is respectively provided with a pressure output port (8) and two or more pressure input ports (3); each pressure input port (3) is communicated with a corresponding pressure input cavity (4), and the pressure output port (8) is communicated with the pressure output cavity (7); the cross section area of each pressure input cavity (4) is equal to that of the pressure output cavity (7). When two or more control handles are operated at the same time, the output flow rate of a hydraulic pump can be equal to thesum of the flow rates required for simultaneous operation of a plurality of actuators, the corresponding speed of the simultaneous operation of the plurality of actuators is increased, and the operation efficiency is further improved.