The invention discloses a voltage transformer with a protection prompting device. The voltage transformer comprises a voltage transformer main body and a built-in fuse with an ejection signal device,wherein an opening is formed in the bottom of an inner cavity of the voltage transformer main body; the fuse with the ejection signal device is internally arranged in a binary line inner cavity of thevoltage transformer main body in a pluggable manner and is fixed through a clamping assembly; the fuse with the ejection signal device comprises a fusion tube, a fuse transmitting device and an announciator; and the fuse transmitting device and the announciator are connected with each other and are arranged at the bottom of the fusion tube. When a fault occurs in a line of a power grid of using the voltage transformer with the protection prompting device, the fuse with the ejection signal device firstly fuses a melt, a built-in impactor of the fuse transmitting device triggers the announciator to eject a signal to prompt the fault, and the fuse plays a role in isolating the transformer after fusing. The melt is broken and the fuse transmitting device ejects the signal, so that a maintainer can easily find out the fault, maintenance of an inspector is facilitated and the workload of the maintainer is reduced.