Liquid droplets are objects of study in many industries due to their wide range of applications, including in agriculture and energy. When studying a droplet with a deformed object inside it, the length or radius of the object inside it will not be directly measured by photographing of the side view due to the refraction effect. In order to solve this problem, this paper analyzes the magnification of the object inside the droplet by geometric optics theory, derives the formula of magnification, and verifies it using practical experiments and simulations to illustrate the validity of the formula. It is also found that the amplification effect decreases as the internal object increases. The conclusions of this paper can correct the size amplification effect of the object inside the droplet due to refraction, which is a guideline for experimental and computational analysis in the field of droplet-related research.