A novel compact optical component aimed at transforming a plane wave into a bottle beam is proposed and demonstrated. This component consists of a cover and aplano-convex lens which has the advantage of simple structure and easy production. The component can generate bottle beam with fixed parameters by modulating paralleling light and achieve the target of turning the size of bottle beam in wide range by replacing the cover. The formation mechanism of bottle beam is analyzed by geometrical optics, the relevant parameters expression is also derived. According to the diffraction integral theory, the distribution of the light field behind the element is derived and the numerical simulation is carried out with Matlab. Using He- Ne laser as light source, the cross sectional intensity distribution of bottle beam in experiment is captured.The results are basically consistent with the simulation.