The invention relates to a method for culturing red algae with high-yield phycocyanin. The method comprises the steps of red algae heterotrophy or polyculture and photoautotrophic cultivation. The photoautotrophic cultivation is performed by taking algae cells obtained by heterotrophism or polyculture as seeds. The invention further relates to a method for quickly accumulating phycocyanin. By adoption of the method, the advantage that the algae cells grow quickly when the red algae are at a heterotrophy or polyculture stage, and plenty of algae seeds are provided for a follow-up photoautotrophic stage. The red algae grow quickly at the photoautotrophic stage, and phycocyanin is accumulated. According to the method, the problems that in the existing photoautotrophic cultivation process of the red algae, the cell growth rate is too low and the content and yield are low when microalgae are utilized to produce phycocyanin can be solved.