The behavior of single water drop impacting an oil layer on the deep water pool was recorded using a high-speed camera. Heptane was used as the target liquid layer on the water pool. A particular phenomenon of double crown can be observed. The formation of double crown is not only related to the impact Weber number of the water droplet, but also the thickness of the oil layer. The critical Weber number for the formation of double crown decreases sharply as the decrease of the oil layer thickness. With the increase of Weber number and the decrease of oil layer thickness, there are four typical phenomena: single crown-jet, single crown-bubble, double crown-bubble and double crown-jet. Moreover, the effects of oil layer thickness and impact Weber number on surface bubble lifetime and the geometry size of crown, crater and jet were quantitatively analyzed. (C)& nbsp;& nbsp;2021 Elsevier Masson SAS. All rights reserved.