Yes, when the sentence is ended with a period, it would be interpreted as a command to wash the speaker's socks.
However, if spoken in a different intonation (ended with a question mark):
You are going to wash my socks?
It would be interpreted as an expression of surprise on the speaker's part that the person they're talking to is going to wash their socks.
There are probably other variations in intonation that might lead to different implications. A lot in English depends on how something is said. But if I were to read your original sentence in absence of other context or vocal cues, yes, that's what I'd assume.