To analyze the quality of front office service by causal analysis, we should first list the problems existing in front office service, including poor waiter attitude, unsatisfactory dishes and unclean room hygiene. Clarifying the problem is the basis of analysis and improvement. Analyze the causes of the listed problems. Through in-depth investigation and observation, find out the reasons for the problems such as poor training of waiters, poor quality of ingredients and careless work of cleaning staff. Be sure to find the root of the problem, not just the symptoms. According to the analyzed reasons, the corresponding improvement measures are formulated. For example, strengthen the training of waiters, strictly implement the procurement standards of ingredients, and increase the work assessment of cleaning staff. Ensure that measures can solve problems in a targeted manner and improve the service quality of the front office. These measures will be implemented in the hotel lobby. At the same time, follow up and evaluate the implementation effect, find problems in time and make adjustments and improvements. Continuous monitoring and improvement is the key to ensure the continuous improvement of front office service quality.