  Compact radio active galactic nuclei (compact radio AGN) are compact ($\leq$
20 kpc), powerful radio sources. Currently, the preferred scenario is that they
are at the early stage of AGN evolution. At present, the research of compact
radio AGN mainly focuses on the radio band, other bands have not been
extensively studied. We present the systemic optical properties and X-ray
emission studies for compact radio AGN, to investigate the accretion
properties, AGN evolution and their X-ray origin. We find that compact radio
AGN have various accretion modes indicated by the accretion rate analysis. In
the radio power-linear size diagram they generally follow the evolutionary
trend towards large-scale radio galaxies with increasing linear size and
decreasing accretion rate. Their hard X-ray emission may be from jet based on
the radio/X-ray relation and fundamental plane of black hole activity.
