Due to the refraction caused by the limited space, small distance between the observation points and the tunnel lining and directional air flow, system errors often occur to horizontal angle survey of CPII control network of long tunnels. In the paper, the actual application of CPII track control network in Liziping tunnel on ChangshaKunming passengerdedicated railway is represented. The causes for and distribution rules of the system error of horizontal angle survey of CPII control network of long tunnels are analyzed on basis of automatic observation and automatic data recording, and countermeasures, such as positive and negative Wtype observation, are proposed.