Understanding whether the "35-year-old phenomenon" exists is crucial for optimizing employment support policies and achieving high-quality, sufficient employment. Based on micro-level data from 2002 to 2022, this paper analyzes age-related trends in four key aspects of China's labor market: income, employment, job transition, and job search. The findings suggest that labor market indicators do not experience a sharp deterioration after age 35. Instead, the so-called phenomenon stems from growing employment uncertainty, driven by the rising risk of unemployment and declining job transition capacity.Specifically: (1) Within each age group, income increases steadily with age, although younger cohorts exhibit higher initial income and faster growth rates; (2) The unemployment rate shows a gradual upward trend after age 35; (3) Among men, job transition ability and its associated income returns begin to decline after age 30; (4) While the cost of job search across transitions decreases with age, the duration of job search following unemployment increases; (5) Due to factors such as childbirth, women face an earlier decline in job transition ability and, between ages 26 and 35, show lower mobility and higher unemployment risks compared to men. This study provides theoretical and empirical support for refining employment support policies.