Composite insulating cable without sheath

The utility model discloses a composite insulating cable without a sheath, which is characterized by comprising a conductive core at center, an inner insulating layer and an outer insulating layer. The conductive core is coated with the inner insulating layer and the outer insulating layer with different colors; the conductive core comprises one or more copper wires or aluminum wires or plated copper wires; the inner insulating layer is prepared from an environmentally friendly flame retardant PVC compound; and the outer insulating layer is prepared from a high flame-retardant environmental protection hard PVC compound. According to the composite insulating cable without a sheath, excellent flame-retardant performance is provided, the oxygen index reaches more than 32, the exterior of each insulating layer possesses high hardness and smoothness, the mechanical wearing when a wire is arranged or passing through a pipe is bearable, the through capability of the wire at the turning position of an installation th