Stem removal is necessary for fresh chilli fruit processing, especially in the Mekong Delta region. In previous studies, the destemming method using clamping belts has been done which allowed to grip and completely separate the stems. However, the control of the gripping force has not yet been implemented, thus causing unable to clamp the stems, or clamping strongly to break the stems. This study focuses on building a force model to control the destemming process, helping to improve the success rate. The mathematical relationship between the gripping force and the measured force on the sensor has been shown. The experimental model was set up and run to evaluate the working ability. Tests were carried out on 1,000 chillies with a successful rate of up to 96.2%. In further studies, this model would be extended to design a destemming system.