Simultaneously generating various motion modes in piezoelectric structure is highly desired for multifunctional actuator featuring high-resolution displacement and high speed,which remain difficult to achieve simultaneously. Traditional piezoelectric actuators are constructed by bonding several piezoelectric and non-piezoelectric stacks and require multisignal excitation, leading to complicated and cumbersome structures. Here, we report a compact actuator designed from a slice of pure piezoceramic metastructure. The metastructure consists of asymmetrically connected units, enabling simultaneous bending and stretching modes under a single signal excitation. Through parametric design for multiple deformation modes, the actuator achieves stable stepping motion with both a high displacement resolution of 3.32 nm and broad driving-speed. Furthermore, with dynamic friction control based on contact-foot trajectory optimization, nearly 0% backward motion and enhanced stepping displacement are achieved, enabling larger velocities. This work proposes a novel inertial actuator based solely on a pure piezoceramic metastructure, advancing compact highperformance actuators.