Lithium-niobate microcavities have not only the ability to resonantly enhance light–matter interaction but also excellent nonlinear optical properties, thereby providing an important platform for nonlinear optical investigations. In this paper, we report the observation of multi-peak spectra in the near infrared range in lithium-niobate microcavities on a chip under the pump of a 1550 nm continuous laser. Such a multi-peak spectrum was attributed to the sum-frequency of the pump laser and its background. The conversion efficiencies of the sum-frequency processes are of the order of 61.5%W-1. The influences of the phenomenon on nonlinear processes were further discussed.