  The measurement of Born cross section of $e^+e^-\to ZH$ process is one of the
major goals of the future Circular Electron Positron Collider, which may reach
a precision of 0.5%. Such unprecedented precision must be guaranteed by both
theoretical and experimental sides, such as the calculations of high order
corrections, the knowledge of the $\sigma^{\mathrm{B}}(e^+e^-\to ZH)$ line
shape. The uncertainty of radiative correction factor due to lack of knowledge
of the $\sigma^{\mathrm{B}}(e^+e^-\to ZH)$ line shape is evaluated in this
work. Therefore, the dedicated data-taking schemes are proposed in order to
precisely calculate the ISR correction factor.
