大三的学生办理澳州留学合适吗？选什么专业有助于移民？

大学毕业比较合适，就你目前的情况。
选择紧缺行业是最好的选择，因为澳洲近年来对于移民政策越收越紧。
以下是最新的紧缺行业表，你可以参照一下
MIGRATION OCCUPATIONS IN DEMAND (MODL) Professionals ASCO code
Accountant 2211-11
Anaesthetist 2312-11
Chemical Engineer 2129-17
Civil Engineer 2124-11
Computing Professional - specialising in CISSP 2231-79
Computing Professional - specialising in E-commerce Security (non-programming) 2231-79
Computing Professional - specialising in Network Security 2231-79
Computing Professional - specialising in SAP 2231-79
Computing Professional - specialising in SIEBEL 2231-79
Dental Specialist 2381-13
Dentist 2381-11
Dermatologist 2312-13
Emergency Medicine Specialist 2312-15
General Medical Practitioner 2311-11
Hospital Pharmacist 2382-11
Medical Diagnostic Radiographer 2391-11
Mining Engineer (excluding Petroleum) 2127-11
Nuclear Medicine Technologist 2391-15
Obstetrician and Gynaecologist 2312-17