Summary: A class of four-dimensional switchable hyperchaotic systems is built by adding an additional state to the three-dimensional switchable chaotic system. When subsystems are hyperchaotic, an identical system parameter is determined according to the bifurcation diagrams of the subsystems. Some of its basic dynamical properties are studied in detail, such as the feature of equilibrium, the phase portraits of hyperchaotic attractor, the Lyapunov exponent and the fractal dimension. A practical circuit is designed to realize these systems.