The research was conducted in order to improve the hydrogen generation efficiency of the electrical plasma technology from tap water by using $TiO_2$ photocatalyst, mixed Cu - $TiO_2$ powder, and mixed Ni - $TiO_2$ powder as the catalysts. Experiments were performed with the pulsed power and nitrogen carrier gas. The result has shown that the hydrogen concentration with the presence of $TiO_2$ powder was created higher than that of without using photocatalyst. The hydrogen concentration with using $TiO_2$ was 3012ppm corresponding to the applied voltage of 16kV, while it without using the $TiO_2$ was 1464ppm at the same condition . The effect of $TiO_2$ powder was strongly detected at the applied voltages of 15kV and 16kV. This phenomena might be resulted from the co-effect of the pulsed power discharge and the activated state of $TiO_2$ photocatalyst. The co-effect of the mixed catalysts such as Cu-$TiO_2$ and Ni-$TiO_2$ (the mixed photocatalyst $TiO_2$ and transition metals) were also investigated. The experimental results showed that, Cu and Ni powder dopants were greatly enhancing the activity of the $TiO_2$ photocatalyst. Under these experimental conditions the extremely high hydrogen concentrations at the optimal point were produced as 4089ppm and 6630ppm, respectively.