His predisposition for the painting appeared in 1876. From 1877 to 1884, he traveled the roads with his father, a itinerant merchant. He joined the neo-impressionist group, Camille Pissarro, Paul Signac and Georges Seurat. First pointillist, he returned to a more classic manner in 1890 and Paul Signac will remove any mention of Louis Hayet in the second edition of his work "From Eugène Delacroix to neo-impressionism" (the manifesto of pointillism). He painted circus scenes and urban landscapes in the spirit of Seurat. He has a workshop in La Frette, and realizes many landscapes of the surroundings. We owe him marines from his travels in Brittany, views of Montmartre where he had a workshop on rue d'Orchampt in 1890. He witnessed the marriage of the painter Georges Tardif in 1894 at the town hall of the 18th arrondissement of Paris. Hayet will devote the end of his career to scientific research on pigments or color, without ceasing to paint.