Lau was born and raised in Macau, high school graduated from Yuet Wah College. He obtained an engineering graduate from the University of Calgary. After three years in the private sector (1982–1984), Lau joined the civil service and worked for the then Leal Senado.
Lau has held various civil service positions:
Assistant technician, Public Works Department
Chief of sector, Public Works Department
Chief of division, Public Works Department
Chief of the Hygiene and Cleansing Department
Vice-president and president of the Leal Senado
Vice-president of the executive board of the Provisional Municipal Council of Macau
President of the Administration Committee of the Civic and Municipal Affairs Bureau, 2002–2007