Milani studied with Lorenzo Pasinelli and Cesare Gennari. He developed a personal mannerism, distancing himself from the late Baroque and rediscovering the style of the Carraccis, studying their works in the home of his patron Count Alessandro Fava and in the collection of Palazzo Magnani. He moved to Rome in 1718 and remained there for many years. He has worked in many churches and has frescoed the Palazzo Doria Pamphili Gallery