Abstract: The traditional mould casting technology is being replaced rapidly by continuous casting in the metallurgical industry of China. In this paper, an automatic measurement and control experiment for the mould metal level of continuous casting is presented, On the basis of introducing and digesting foreign techniques, We have developed a FT-8 type molten metal level control device, of which the main technical specifications attained the same level as the foreign ones of the 80′s. The high-voltage generator of this device was built in the probe instead of in the main body, and double signal transmission line and photoelectricity coupler had been adopted. All these make it possible for the device to have strong anti-interference capabilities, to increasethe protection ability for the main body and to reduce the requirements for the insultative properties of the transmission line as well. Its application shows that this device can meet the needs of production, and an economical benefit of 1.94 million yuan has been obtained after it is applied in the steel plant No.2 of Anshan Iron and Steel Complex.