"跳得像蚱蜢一样" can be translated as "jump like a grasshopper" or more naturally expressed as "hop around like a grasshopper" in English, depending on the context.
If you specifically want to emphasize the action of jumping in a manner similar to a grasshopper, "hop around like a grasshopper" would be a vivid and fitting choice. Here, "hop" is a verb that describes the short, quick jumps made by small animals like grasshoppers.
So, "蚱蜢似地跳" can be translated as "hop around like a grasshopper".