To enhance thermal stability while keeping low driven current is difficult in traditional domain wall (DW) motion devices. The increasing of energy barrier for thermal stability inevitably results in the enhancement of driven current. We numerically investigate depinning field (H depin) and critical current density (J c) for DW motion as a function of uniaxial magnetic anisotropy (K u) in vertical DW motion memory with artificial ferromagnet. It is found that H depin and J c show different K u dependence. The results indicate that it is promising to simultaneously achieve high thermal stability and low driven current in artificial ferromagnet based DW motion devices.