"制陶坯的工人" can be translated into English as "worker who makes ceramic blanks" or "pottery blank maker".
"Worker who makes ceramic blanks" clearly describes the job and the product (ceramic blanks) they produce.
"Pottery blank maker" is a more concise and specific term, directly referring to someone who makes the initial, undecorated form of pottery (the blank).
Both translations are accurate, and the choice between them may depend on the context and the desired level of specificity.