The utility model belongs to the technical field of fluid machinery and engineering equipment and particularly relates to a six working condition both-way tidal power generation water turbine adopting a new guide vane arrangement form and a guide vane type line. A water turbine assembly comprises a water inlet pipe, a bulb head, a pipe type seat, a guide vane, a rotary wheel and a tail water pipe. A shape of the guide vane is designed and the new guide vane type line is adopted so that flow is smoother and resistance loss in a flow channel is small. A structure and an arrangement method of the guide vane are designed and the largest opening degree of the guide vane reaches up to 100 degrees so that excess flow capacity of the water turbine is enlarged. Compared with a common tidal assembly, efficiency of forward and backward water turbine is improved, generation capacity is improved, vibration and pressure pulsation are reduced and operation stability of the water turbine can be improved.