The invention discloses a network-side circuit of an electric locomotive unit, which comprises two network-side circuit bodies with pantographs. Each network-side circuit body consists of a high-voltage transformer, the pantograph, a high-voltage isolating switch, a main circuit breaker, a grounding switch, a lightning arrestor, a primary-side high-voltage current transformer, a transformer, a primary-side grounding current transformer and a shaft end grounding device. The high-voltage circuit of the electric locomotive unit further comprises a high-voltage circuit body without a pantograph, the high-voltage circuit consists of a main circuit breaker, a grounding switch, a lightning arrestor, a primary-side high-voltage current transformer, a transformer, a primary-side grounding current transformer and a shaft end grounding device. The three high-voltage circuit bodies are connected by roof high-voltage buses and high-voltage connecting cables. The network-side circuit of the electric locomotive unit can meet the requirement of heavy-load and high-power traction, an optional network-side high-voltage electric component can be isolated when breaking down, and power loss of an integral locomotive is minimized assuredly after fault isolation.