  The Chinese Space Station Optical Survey (CSS-OS) is a major science project
of the Space Application System of the China Manned Space Program. This survey
is planned to perform both photometric imaging and slitless spectroscopic
observations, and it will focus on different cosmological and astronomical
goals. Most of these goals are tightly dependent on the accuracy of photometric
redshift (photo-z) measurement, especially for the weak gravitational lensing
survey as a main science driver. In this work, we assess if the current filter
definition can provide accurate photo-z measurement to meet the science
requirement. We use the COSMOS galaxy catalog to create a mock catalog for the
CSS-OS. We compare different photo-z codes and fitting methods that using the
spectral energy distribution (SED) template-fitting technique, and choose to
use a modified LePhare code in photo-z fitting process. Then we investigate the
CSS-OS photo-z accuracy in certain ranges of filter parameters, such as band
position, width, and slope. We find that the current CSS-OS filter definition
can achieve reasonably good photo-z results with sigma_z~0.02 and outlier
fraction ~3%.
