The probe type ice detector technique is adapted by traditional civil or transport aircraft, which is quite mature to detect regular size droplet. But the capability to detect and recognize supercooled large droplet (SLD) still needs to be explored and studied. Aiming at the icing detector with a dualspindle structure, the icing characteristics of the probe surface under both SLD and conventional small droplets condition were studied. The design principle of the dualspindle structure is analyzed base on impinged area and droplet trajectory character of the SLD. The 3D icing software FENSAPICE is adapted to compute the airflow filed, droplet field and the icing accumulation. The icing distribution on the surface of detector of different droplet diameters is obtained. The influence on icing distribution and droplet trajectory under typical condition with angle of attack (AOA) was studied. Base on the principle of the optical fiber sensor, the icing information at different location on the probe surface is obtained in ice wind tunnel test, and compared with the simulation results. The research results show that the dual spindle structure has obviously different icing distribution under SLD and conventional small droplets condition, and the existence of SLD icing conditions can be judged by icing conditions at different positions of the detector.