"A horse moving with the sliding step (a specific gait in traditional Chinese equestrian arts or possibly referring to a unique walking style in certain contexts)" could be a way to translate "以溜步法走的马".
However, it's worth noting that "溜步法" (liū bù fǎ) might be a more specialized or traditional term, possibly related to a particular style of horse-riding or horse-walking in Chinese culture. If it refers to a specific, well-known gait or technique in equestrian circles, a more precise translation might require additional context or expertise in that field.
In a more general or simplified context, you could also say "a horse walking with a sliding gait" or "a horse moving in a sliding manner," depending on the exact meaning you intend to convey.