Why does my ABS fuse blow so quickly

There would be a short somewhere, scan for ABS codes, this would point you in the right direction for a fix.

wouldn't hurt to check the wiring going to all the speed sensors at each wheel. they can be susceptible to damage in that area, slush, road salt, etc. or it could be rubbing on something and causing the short.

Putting a scanner to check would be a lot faster, then you are not pulling each wheel searching for the problem. If it is in the wheel sensor, the scanner will tell you which one it is.

The fuse blows to protect the circuit from an over current condition. Excessive current can melt wires and cause fires so resist the temptation of installing a higher amperage fuse. Check with a scanner and have close look at the wiring and sensors associated with the ABS system. Proper diagnosis may require a trained mechanic.