The work aims to analyze the change of contact state between electrode and substrate in different modes of electrode movement and study its influence on the discharge mechanism of electric spark overlaying. The continuous discharge tests of rotating electrode and ultrasonic vibrating electrode, and the deposition efficiency tests of rotating electrode and ultrasonic vibrating electrode were carried out. The continuous discharge voltage and current waveforms of rotating electrode and ultrasonic vibrating electrode, the contact state and relative motion between electrode and substrate were analyzed. The discharge types of rotating electrode include short-circuit discharge, gap discharge, and a type of mixed discharge. The discharge types of ultrasonic vibrating electrode are short circuit discharge, gap discharge, and six types of mixed discharge. Under the same discharge parameters, the average current of short circuit discharge of rotating electrode is 11.29 kA and the average current of gap discharge is 6.9 kA. And the transfer coefficient is 79%. the average current of short circuit discharge of ultrasonic vibrating electrode is 6.0 kA and the average current of gap discharge is 3.66 kA and the transfer coefficient is 92%. The movement of electrode affects the state of contact point between electrode and substrate, such as the contact gap, contact area, and contact resistance, etc., thus affecting the discharge type, discharge current, and deposition efficiency. There is a rotational movement in a tangential direction between rotating electrode and substrate, the contact resistance and the change of gap at contact point are small, which results in large circuit discharge and fewer discharge types. There is a up and down ultrasonic vibration between ultrasonic vibrating electrode and substrate, the contact resistance is large and the change of gap at contact point has a wide range and is rapid, which results in more discharge types.