A pen, a method for detecting a pen, and a touch system are disclosed. The pen is configured to operate on a touch panel. The pen includes a controller, a transmitting electrode, and a receiving electrode. The transmitting electrode and the receiving electrode are at different positions of the pen. The receiving electrode is configured to receive a first signal transmitted by the touch panel and transmit the first signal to the controller. The controller is configured to receive the first signal, determine an inclination angle between the pen and the touch panel according to a signal amount of the first signal, generate a second signal by using an encoding format corresponding to the inclination angle, and transmit the second signal to the transmitting electrode. The transmitting electrode is configured to receive the second signal and transmit the second signal to the touch panel.